Abstract : This report presents a procedure for analytically correcting for the effect of wind (dewinding) on a hovering helicopter. This procedure will be much more cost effective than the current method which requires lengthy delays until the wind speed drops below two knots. Dewinding is accomplished by application of the equations of motion and consideration of control changes to flight test data recorded on an incremental digital recording system. An experimental program is outlined to determine first the effective wind acting on a hovering helicopter and second the effect this wind has on the helicopter. (Author)